- * Reverse CRC-32C table
- */
-static const u32 crc32c_rev_table[256] = {
- 0x00000000L,0x05EC76F1L,0x0BD8EDE2L,0x0E349B13L,
- 0x17B1DBC4L,0x125DAD35L,0x1C693626L,0x198540D7L,
- 0x2F63B788L,0x2A8FC179L,0x24BB5A6AL,0x21572C9BL,
- 0x38D26C4CL,0x3D3E1ABDL,0x330A81AEL,0x36E6F75FL,
- 0x5EC76F10L,0x5B2B19E1L,0x551F82F2L,0x50F3F403L,
- 0x4976B4D4L,0x4C9AC225L,0x42AE5936L,0x47422FC7L,
- 0x71A4D898L,0x7448AE69L,0x7A7C357AL,0x7F90438BL,
- 0x6615035CL,0x63F975ADL,0x6DCDEEBEL,0x6821984FL,
- 0xBD8EDE20L,0xB862A8D1L,0xB65633C2L,0xB3BA4533L,
- 0xAA3F05E4L,0xAFD37315L,0xA1E7E806L,0xA40B9EF7L,
- 0x92ED69A8L,0x97011F59L,0x9935844AL,0x9CD9F2BBL,
- 0x855CB26CL,0x80B0C49DL,0x8E845F8EL,0x8B68297FL,
- 0xE349B130L,0xE6A5C7C1L,0xE8915CD2L,0xED7D2A23L,
- 0xF4F86AF4L,0xF1141C05L,0xFF208716L,0xFACCF1E7L,
- 0xCC2A06B8L,0xC9C67049L,0xC7F2EB5AL,0xC21E9DABL,
- 0xDB9BDD7CL,0xDE77AB8DL,0xD043309EL,0xD5AF466FL,
- 0x7EF1CAB1L,0x7B1DBC40L,0x75292753L,0x70C551A2L,
- 0x69401175L,0x6CAC6784L,0x6298FC97L,0x67748A66L,
- 0x51927D39L,0x547E0BC8L,0x5A4A90DBL,0x5FA6E62AL,
- 0x4623A6FDL,0x43CFD00CL,0x4DFB4B1FL,0x48173DEEL,
- 0x2036A5A1L,0x25DAD350L,0x2BEE4843L,0x2E023EB2L,
- 0x37877E65L,0x326B0894L,0x3C5F9387L,0x39B3E576L,
- 0x0F551229L,0x0AB964D8L,0x048DFFCBL,0x0161893AL,
- 0x18E4C9EDL,0x1D08BF1CL,0x133C240FL,0x16D052FEL,
- 0xC37F1491L,0xC6936260L,0xC8A7F973L,0xCD4B8F82L,
- 0xD4CECF55L,0xD122B9A4L,0xDF1622B7L,0xDAFA5446L,
- 0xEC1CA319L,0xE9F0D5E8L,0xE7C44EFBL,0xE228380AL,
- 0xFBAD78DDL,0xFE410E2CL,0xF075953FL,0xF599E3CEL,
- 0x9DB87B81L,0x98540D70L,0x96609663L,0x938CE092L,
- 0x8A09A045L,0x8FE5D6B4L,0x81D14DA7L,0x843D3B56L,
- 0xB2DBCC09L,0xB737BAF8L,0xB90321EBL,0xBCEF571AL,
- 0xA56A17CDL,0xA086613CL,0xAEB2FA2FL,0xAB5E8CDEL,
- 0xFDE39562L,0xF80FE393L,0xF63B7880L,0xF3D70E71L,
- 0xEA524EA6L,0xEFBE3857L,0xE18AA344L,0xE466D5B5L,
- 0xD28022EAL,0xD76C541BL,0xD958CF08L,0xDCB4B9F9L,
- 0xC531F92EL,0xC0DD8FDFL,0xCEE914CCL,0xCB05623DL,
- 0xA324FA72L,0xA6C88C83L,0xA8FC1790L,0xAD106161L,
- 0xB49521B6L,0xB1795747L,0xBF4DCC54L,0xBAA1BAA5L,
- 0x8C474DFAL,0x89AB3B0BL,0x879FA018L,0x8273D6E9L,
- 0x9BF6963EL,0x9E1AE0CFL,0x902E7BDCL,0x95C20D2DL,
- 0x406D4B42L,0x45813DB3L,0x4BB5A6A0L,0x4E59D051L,
- 0x57DC9086L,0x5230E677L,0x5C047D64L,0x59E80B95L,
- 0x6F0EFCCAL,0x6AE28A3BL,0x64D61128L,0x613A67D9L,
- 0x78BF270EL,0x7D5351FFL,0x7367CAECL,0x768BBC1DL,
- 0x1EAA2452L,0x1B4652A3L,0x1572C9B0L,0x109EBF41L,
- 0x091BFF96L,0x0CF78967L,0x02C31274L,0x072F6485L,
- 0x31C993DAL,0x3425E52BL,0x3A117E38L,0x3FFD08C9L,
- 0x2678481EL,0x23943EEFL,0x2DA0A5FCL,0x284CD30DL,
- 0x83125FD3L,0x86FE2922L,0x88CAB231L,0x8D26C4C0L,
- 0x94A38417L,0x914FF2E6L,0x9F7B69F5L,0x9A971F04L,
- 0xAC71E85BL,0xA99D9EAAL,0xA7A905B9L,0xA2457348L,
- 0xBBC0339FL,0xBE2C456EL,0xB018DE7DL,0xB5F4A88CL,
- 0xDDD530C3L,0xD8394632L,0xD60DDD21L,0xD3E1ABD0L,
- 0xCA64EB07L,0xCF889DF6L,0xC1BC06E5L,0xC4507014L,
- 0xF2B6874BL,0xF75AF1BAL,0xF96E6AA9L,0xFC821C58L,
- 0xE5075C8FL,0xE0EB2A7EL,0xEEDFB16DL,0xEB33C79CL,
- 0x3E9C81F3L,0x3B70F702L,0x35446C11L,0x30A81AE0L,
- 0x292D5A37L,0x2CC12CC6L,0x22F5B7D5L,0x2719C124L,
- 0x11FF367BL,0x1413408AL,0x1A27DB99L,0x1FCBAD68L,
- 0x064EEDBFL,0x03A29B4EL,0x0D96005DL,0x087A76ACL,
- 0x605BEEE3L,0x65B79812L,0x6B830301L,0x6E6F75F0L,
- 0x77EA3527L,0x720643D6L,0x7C32D8C5L,0x79DEAE34L,
- 0x4F38596BL,0x4AD42F9AL,0x44E0B489L,0x410CC278L,
- 0x588982AFL,0x5D65F45EL,0x53516F4DL,0x56BD19BCL
-};
-
-/*
- * Calculate a 4-byte suffix to match desired CRC32C
- *
- * @current_crc: CRC32C checksum of all bytes before the suffix
- * @desired_crc: the checksum that we want to get after adding the suffix
- *
- * Outputs: @suffix: pointer to where the suffix will be written (4-bytes)
- */
-static void find_collision_calc_suffix(unsigned long current_crc,
- unsigned long desired_crc,
- char *suffix)
-{
- int i;
-
- for(i = 3; i >= 0; i--) {
- desired_crc = (desired_crc << 8)
- ^ crc32c_rev_table[desired_crc >> 24 & 0xFF]
- ^ ((current_crc >> i * 8) & 0xFF);
- }
- for (i = 0; i < 4; i++)
- suffix[i] = (desired_crc >> i * 8) & 0xFF;
-}
-
-/*
- * Check if suffix is valid according to our file name conventions
- */
-static int find_collision_is_suffix_valid(const char *suffix)
-{
- int i;
- char c;
-
- for (i = 0; i < 4; i++) {
- c = suffix[i];
- if (c < ' ' || c > 126 || c == '/')
- return 0;
- }
- return 1;
-}
-
-static int find_collision_brute_force(struct name *val, u32 name_len)
-{
- unsigned long checksum;
- int found = 0;
- int i;
-
- checksum = crc32c(~1, val->val, name_len);
- memset(val->sub, ' ', name_len);
- i = 0;
- while (1) {
- if (crc32c(~1, val->sub, name_len) == checksum &&
- memcmp(val->sub, val->val, val->len)) {
- found = 1;
- break;
- }
-
- if (val->sub[i] == 126) {
- do {
- i++;
- if (i >= name_len)
- break;
- } while (val->sub[i] == 126);
-
- if (i >= name_len)
- break;
- val->sub[i]++;
- if (val->sub[i] == '/')
- val->sub[i]++;
- memset(val->sub, ' ', i);
- i = 0;
- continue;
- } else {
- val->sub[i]++;
- if (val->sub[i] == '/')
- val->sub[i]++;
- }
- }
- return found;
-}
-
-static char *find_collision(struct metadump_struct *md, char *name,
- u32 name_len)
-{
- struct name *val;
- struct rb_node *entry;
- struct name tmp;
- int found;
- int i;
-
- tmp.val = name;
- tmp.len = name_len;
- entry = tree_search(&md->name_tree, &tmp.n, name_cmp, 0);
- if (entry) {
- val = rb_entry(entry, struct name, n);
- free(name);
- return val->sub;
- }
-
- val = malloc(sizeof(struct name));
- if (!val) {
- error("cannot sanitize name, not enough memory");
- free(name);
- return NULL;
- }
-
- memset(val, 0, sizeof(*val));
-
- val->val = name;
- val->len = name_len;
- val->sub = malloc(name_len);
- if (!val->sub) {
- error("cannot sanitize name, not enough memory");
- free(val);
- free(name);
- return NULL;
- }
-
- found = find_collision_brute_force(val, name_len);
-
- if (!found) {
- warning(
-"cannot find a hash collision for '%.*s', generating garbage, it won't match indexes",
- val->len, val->val);
- for (i = 0; i < name_len; i++) {
- char c = rand_range(94) + 33;
-
- if (c == '/')
- c++;
- val->sub[i] = c;
- }
- }
-
- tree_insert(&md->name_tree, &val->n, name_cmp);
- return val->sub;
-}
-
-static void sanitize_dir_item(struct metadump_struct *md, struct extent_buffer *eb,
- int slot)
-{
- struct btrfs_dir_item *dir_item;
- char *buf;
- char *garbage;
- unsigned long name_ptr;
- u32 total_len;
- u32 cur = 0;
- u32 this_len;
- u32 name_len;
- int free_garbage = (md->sanitize_names == 1);
-
- dir_item = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
- total_len = btrfs_item_size_nr(eb, slot);
- while (cur < total_len) {
- this_len = sizeof(*dir_item) +
- btrfs_dir_name_len(eb, dir_item) +
- btrfs_dir_data_len(eb, dir_item);
- name_ptr = (unsigned long)(dir_item + 1);
- name_len = btrfs_dir_name_len(eb, dir_item);
-
- if (md->sanitize_names > 1) {
- buf = malloc(name_len);
- if (!buf) {
- error("cannot sanitize name, not enough memory");
- return;
- }
- read_extent_buffer(eb, buf, name_ptr, name_len);
- garbage = find_collision(md, buf, name_len);
- } else {
- garbage = generate_garbage(name_len);
- }
- if (!garbage) {
- error("cannot sanitize name, not enough memory");
- return;
- }
- write_extent_buffer(eb, garbage, name_ptr, name_len);
- cur += this_len;
- dir_item = (struct btrfs_dir_item *)((char *)dir_item +
- this_len);
- if (free_garbage)
- free(garbage);
- }
-}
-
-static void sanitize_inode_ref(struct metadump_struct *md,
- struct extent_buffer *eb, int slot, int ext)
-{
- struct btrfs_inode_extref *extref;
- struct btrfs_inode_ref *ref;
- char *garbage, *buf;
- unsigned long ptr;
- unsigned long name_ptr;
- u32 item_size;
- u32 cur_offset = 0;
- int len;
- int free_garbage = (md->sanitize_names == 1);
-
- item_size = btrfs_item_size_nr(eb, slot);
- ptr = btrfs_item_ptr_offset(eb, slot);
- while (cur_offset < item_size) {
- if (ext) {
- extref = (struct btrfs_inode_extref *)(ptr +
- cur_offset);
- name_ptr = (unsigned long)(&extref->name);
- len = btrfs_inode_extref_name_len(eb, extref);
- cur_offset += sizeof(*extref);
- } else {
- ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
- len = btrfs_inode_ref_name_len(eb, ref);
- name_ptr = (unsigned long)(ref + 1);
- cur_offset += sizeof(*ref);
- }
- cur_offset += len;
-
- if (md->sanitize_names > 1) {
- buf = malloc(len);
- if (!buf) {
- error("cannot sanitize name, not enough memory");
- return;
- }
- read_extent_buffer(eb, buf, name_ptr, len);
- garbage = find_collision(md, buf, len);
- } else {
- garbage = generate_garbage(len);
- }
-
- if (!garbage) {
- error("cannot sanitize name, not enough memory");
- return;
- }
- write_extent_buffer(eb, garbage, name_ptr, len);
- if (free_garbage)
- free(garbage);
- }
-}
-
-static void sanitize_xattr(struct metadump_struct *md,
- struct extent_buffer *eb, int slot)
-{
- struct btrfs_dir_item *dir_item;
- unsigned long data_ptr;
- u32 data_len;
-
- dir_item = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
- data_len = btrfs_dir_data_len(eb, dir_item);
-
- data_ptr = (unsigned long)((char *)(dir_item + 1) +
- btrfs_dir_name_len(eb, dir_item));
- memset_extent_buffer(eb, 0, data_ptr, data_len);
-}
-
-static void sanitize_name(struct metadump_struct *md, u8 *dst,
- struct extent_buffer *src, struct btrfs_key *key,
- int slot)
-{
- struct extent_buffer *eb;
-
- eb = alloc_dummy_eb(src->start, src->len);
- if (!eb) {
- error("cannot sanitize name, not enough memory");
- return;
- }
-
- memcpy(eb->data, src->data, src->len);
-
- switch (key->type) {
- case BTRFS_DIR_ITEM_KEY:
- case BTRFS_DIR_INDEX_KEY:
- sanitize_dir_item(md, eb, slot);
- break;
- case BTRFS_INODE_REF_KEY:
- sanitize_inode_ref(md, eb, slot, 0);
- break;
- case BTRFS_INODE_EXTREF_KEY:
- sanitize_inode_ref(md, eb, slot, 1);
- break;
- case BTRFS_XATTR_ITEM_KEY:
- sanitize_xattr(md, eb, slot);
- break;
- default:
- break;
- }
-
- memcpy(dst, eb->data, eb->len);
- free(eb);
-}
-
-/*